New Alzheimer's association workgroup criteria underestimate syndromes in Alzheimer's disease definition.

The biological definition of Alzheimer's disease promoted by the Alzheimer's Association Working Group's new criteria relegates cognitive impairment to the background when defining the disease. However, cognitive syndromes, as plaques and tangles, are important biological phenomena, are part of the disease and not of the illness, and are objectively investigable. When well delineated, they show a close correlation with brain anatomy and neuropathology and are also few, relatively invariable, well-defined and well distinguishable from each other. Therefore, their detection retains a high value in suggesting the presence of the disease, which still must be confirmed by principle of exclusion.